The honest answer: it depends. A battery isn't always the right financial decision — even if you have solar. Here's how to think through whether one makes sense for your household.
What a Battery Actually Does
Your solar panels generate electricity during the day. If you're not home — or not using much power — excess generation gets exported to the grid. In Victoria, you'll typically receive around 4–6 cents/kWh for that export.
A battery stores that excess generation instead of exporting it. You then use that stored electricity in the evening or overnight — avoiding buying from the grid at ~28–32 cents/kWh. The arbitrage between the export rate and the avoided purchase rate is where the battery earns its value.
When a Battery Makes Strong Financial Sense
High evening usage
If your household uses most of its electricity in the evening — cooking, appliances, entertainment — a battery means you use stored solar instead of buying from the grid at peak rates.
Away from home during the day
If no one is home during solar generation hours, you export most of your production. A battery captures that and shifts it to when you need it.
An EV to charge overnight
Charging an EV from stored solar rather than from the grid overnight can significantly improve the battery's financial case.
Power security matters to you
If you want backup during grid outages, a battery provides that — independent of the pure financial calculation.
When a Battery May Not Improve Your Payback
High daytime usage
If someone is home all day using electricity — running appliances, working from home — you self-consume most of your solar directly. There's less excess to store, and the battery has less to do.
Small solar system
A small system may not generate significant excess to store. The battery sits mostly empty.
Very low overnight usage
If your household uses very little electricity overnight, a battery sized for typical coverage will be oversized for your actual needs.
The HEA Approach
We model both scenarios using your actual interval data — solar alone, and solar plus battery. We show you the projected payback for each and the difference in upfront cost.
Sometimes a battery meaningfully shortens payback or improves financial return. Sometimes it extends it. We'll tell you which is true for your household — and we won't push a battery because it increases the sale value.
Get the comparison for your home
We'll model solar-only vs solar-plus-battery using your actual usage data. You'll see the financial case clearly before you decide.
Get My Solar Estimate